A high-level dispute over which senior government officials pushed the unverified Steele dossier amid efforts to surveil the Trump campaign has broken out into the open again, after it emerged that Attorney General William Barr appointed a U.S. attorney to examine the origins of the Russia investigation and determine if the FBI and DOJ's actions were "lawful and appropriate."

Comey, a former FBI director, sent an email to subordinates in late 2016 indicating Brennan, a former CIA director, wanted to include materials from the dossier in the intelligence community assessment, known as the ICA, Fox News reported.

A former CIA official speaking on Brennan's behalf is disputing the assertion. The former official told Fox that Brennan and James Clapper, a former director of national intelligence, opposed Comey's push to include Steele dossier information in the ICA.

The dispute pits two former intelligence community officials against each other at a time when the Justice Department is investigating how government agencies like the FBI and CIA handled the dossier, which former British spy Christopher Steele authored and the Clinton campaign and Democratic National Committee funded.